This invention relates to a method and an apparatus for sticking a film to a lead frame, and more particularly to, a method and an apparatus for sticking a film to a lead frame by which a punched film is prevented from creating burrs before sticking to the lead frame.
In general, a lead frame, on which an IC or LSI chip is attached, are fabricated by sticking a strip of film to a tip portion of leads of the lead frame so as to keep them from a position level difference or a position shift of the tip portion thereof. In an LOC (Lead on Chip) type lead frame, a film having thermally activating adhesive layers on the both surface thereof is commonly used for sticking the leads of the lead frame on the chip.
In a conventional method for sticking a film to a lead frame, a film is punched to provide a punched film having a predetermined shape by using a punch and a die cooperating with each other. The punched film is applied on a bead frame which is heated on a heating plate. Thus, the punched film is thermally compressed and adhesively attached on a lead portion of the lead frame.
In the conventional method for sticking a film to a lead frame, however, there is a disadvantage in that burrs, such as fiber-like burrs or tiny chips, may occur on a cutting end of the punched film, because compressive stress is given to the film by the shearing movement of the punch and the die, thereby a crack at the cutting end is created and may results in such burrs. If such punched films with burrs are stick to a lead frame, burrs may blow off from the film and stick to a fine tip portion of the lead of the lead frame, thereby resulting in serious defect in wire-bonding performance.